But, Holt — whose father, Rush Holt Sr., served as a West Virginia senator from 1935-1941 — added: “To express interest is not the same thing as a campaign announcement.’’

Succeeding Lautenberg, he suggested, will be a big job.

“He’s a real hard worker, he doesn’t give up; he’s persistent. He has stopped not only smoking on airplanes but he set new standards for blood alcohol level, drunk driving,’’ Holt said.

“You could fill an entire stadium of people who are alive today because of Frank Lautenberg and they don’t know it. They don’t know who they are. But there are that many people out there.’’

Holt, who has a doctorate in physics and has worked at Princeton University, was asked by Malzberg about the giant meteor that slammed into Russia, injuring 1,100 people.

“It packs a lot of energy. So in fact it explodes with the force of a small atomic bomb, probably,’’ Holt said. “There’s tons of material that rains down on the Earth but most of it is dust particles … grains of sand.

“You see a shooting star at night; it’s just a tiny pebble usually. But it has so much energy at that speed that it makes a spectacular show for a split second.’’